it's not something I'd label as "nice". It's a military alliance, FFS.
Said the objective is nice. The objective of the UN and NATO is supposed to be world nuclear disarmament, world peace, nice dreamy stuff like that. What constitutes an outside attack if everyone is aligned? Though as said before, nice, but probably wont ever happen, unless there's a true world government some day.
If you can make Russia and China join, then fine.
The only thing I can personally do about these matters, is offer brilliant insight.